Hinge for rules and protractors



(No Model.)

J. K. LOVE.

HINGE FOR RULES AND PROTRATORS. y No. 512,199. Patented Jan. 2, 1894.

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NITED STATES ATENT FFCE@ JOI-IN K. LOVE, OF SILVERTON, ASSIGNOR OF ONE-THIRD TO ELMORE CAMERON,- OF CINCINNATI, OHIO.

HINGE FOR RULES AND PROTRACTORS.

SPECIFICATION forming part of Letters Patent No, 512,199, dated January 2, 1894.

Serial No. 469,737. (No model.)

To @ZZ whom, it 11e/ay concern:

Be it known that I, JOHN K. LOVE, a citizen of the United States, and a resident of Silverton, in the county ofjHamiiton and Stat-e of Ohio, have invented certain new and useful Improvements in Lock-Hinges for Rules and Protractors, of which the following is a specification. I

The several features of my invention and the various advantages resulting from their use, conjointly or otherwise, will be apparent from the following description and claims.

In the accompanying drawings making a part of this specification, and in which like letters of reference indicate corresponding parts,-Figure l is a side elevation of a rule illustrating my invention, the rule shown open. Fig. 2 is a side elevation of said rule, closed. Fig. 3 is a side elevation of the same rule partly opened, so that the arms make an angle between them of forty five degrees. Fig. 4t is a View of the joint Whereby the two arms of the rule are connected together, the upper portion of one arm being removed, and the connection pivot being s hown in section. Fig. 5 is a transverse section of the rule taken in the plane of the dotted line 5, 5, of Fig. l, that side of the section being shown which faces toward the left hand side of thesheet of drawings. Fig. 6 is a view of that portion of the lock joint which belongs to one varm of the rule and slides between th'e interlocking portions of the other arm. Fig. 7 is an enlarged view of that poi'- tion of Fig. 5 which consists of the set screw H and of portions of the rule immediately adjacent thereto.

A represents one arm. of the rule, and B the other arm. The proportionate size of either arm to the other may be varied as desired. As one of such arms is usually made narrower and shorter than the other, I have for the purposes of illustration, thus shown the arm B. That end portion of arm B which interlocks with arm A is formed substantially as shown in Fig. 6, viz: Each side of said end portion is recessed leaving a tongue C and a recess K on each side thereof, that is to say, above and below. This tongue has an inclined edge C', ending at a curved edge O2. The latter is present as the outside rim of a curved slot C3. At the outer end of this curved slot isa straight portion C4, at right angles to the length of the said arm B, and the remaining portion O5 oi` the edge of the tongue is in line with and is a continuation of the inner edge of the arm B. An opening C in the tongue C receives the pivot connection between the arms A and B. The curve of the slot C3 is a true arc described by radius from the center of the pivot opening O6.

The mode of making the recess K. leaves a raised boundary B', continued in a straight edge B2, extending to the adjacent end of the arm.

. At the inner end of the slot O3 is a circular recess C7 Whose center is in the central longitudinal line of the said slot, and of a diameter larger than the width of the slot.

The objects of the foregoing construction will be shortly hereinafter described.

The adjacent end of the arni A is formed as follows, viz: The arm A is provided with an extension A2, straight on its lower edge A5, curved on edge A3, and straight on its upper side A4. The curve ot the boundary B2 of arm B and the curve A3 of the edge A3 of arm A are concentric. When the rule is in operation, the boundary B2 slides or moves against the edge A3 and when the rule is a right angled one, the edge B2 rests against the straight edge A4 of arm A. The end A2 is mortised and the adjacent portion of the end of arm A is hereinafter described. The recess D formed by the said mortise receives the tongue C of the arm B. The upper edge of a part of the end of the arm A is cut away so that the edge B3 of the arm B may come into place against it as shown. The corner portion A of arm B overlaps the end of the edge B3 as shown. The inner edge or bottoni of the recess D has an inclined portion D and a concavelycurved portion D2, and these respectively [it against IOO lower side of the mortise D. This pivot has a head F2 preferably beveled on itsunder side after the manner of the ordinary screw. A convenient means of turning it is by a slot E5, in the head like the ordinary screw. Such conformation of the head allows the screw to be sunk so that the upper surface of the head is flush with the outer surface of the side D5 of the mortise.

The set screw H for setting the arms of the rule at a given angle is of a novel construction and the construction of the parts it is combined with is also novel, to wit: This set screw H has a screw threaded shank H, en-

gaging a female screw in an opening D5 in the lower side D5 of the arm A. This shank H passes up through the curved slots C2, and terminates in an enlarged disk H2, whose thickness is not greater than the depth of the recess C7 of the curved slot C2, and is of slightly less diameter, so that it can enter said recess. In the under side of the upper side D5 of the arm A is a recess D5, just wide enough to receive the disk H2. This recess D7 is curved and extends over the curved slot C3 and concentric therewith. Above this recess D7 is a concentric opening D8 of less diameter than the said recess, and

,extending up through the side D5. The upper shank or head H3 of the set screw H extends from the disk H2 up and into this opening. The preferred means of rotating it (the screw) consists of a slot H4 in the head of the latter. Thus both the screw pivot E and the set screw H have the advantage of being operated by a common screw driver.

Obviously the set screw H when once in place, as aforementioned, cannot be withdrawn. Various ways of getting the set screw H in place can be employed.

A preferred means of getting the set screw H in place is by making one of the sides D5 or D5 removable.

In the present instance, a portion D12 of the arm A back of the lines D5, D2is cut away as far as D10, and to the thickness of the side D5, the latter is also removed with said portion D12. This plate thus cut oil", or a new plate, the equivalent of the aforesaid portion, and in which the two plates D5 and D10 are integral, is substituted. The set screw H is located in position, and the plate D5, D12 is then put in place and secured there preferably by rivets or screws I, I, I.

The modein which my improved instrument operates is at once simple and effective, viz:- The two arms having been united and the pivot E having been put in place, the rule is ready for use. When the rule is to be used as a square, the arms are placed in the posision shown in Fig. 1. The set screw H is now screwed down as far as it will go. This operation places the enlargement or disk H2 of it, in the recess C7 of the tongue C. As the disk H2 quite closely ts this recess, the arms of the square are securely and rigidly held in position by this disk. Furthermore the screw of shank H causes the disk I-l2to press the tongue Chard against the lower side D5 of arm A and thus aid in causing the arms to remain rigidly in one and the same horizontal plane. When the rule is to be employed to give an angle other than a right angle, the set screw His unscrewed,and thus raised until the disk H2 is elevated out of the recess C7. The arms A and B are now moved in reference to each other until they make the desired angle between them. Then the s et screw H is screwed down, and thus the dlsk H2 1s forced down upon the tongue C, and presses the latter against the lower side D5. This sets the arms and they will remain in this posi- Y tion until the set screw H is loosened, and

then the arms can be moved with reference to one another.

It will be observed that the shank H' of the set screw is at all times in the curved slot C5, and that the disk H2 travels above it, the edges of the disk overlapping the slot. The disk H2 performs the functions of a rivet at the lower end of the set screw an of an enlarged head on the set screw H. .It acts as a clamp, and at the inner end of the slot when in the recess C7 acts as a stop.

What I claim as new and of my invention, and desire to secure by Letters Patent, is

1. A rule having arms A and B, pivoted together, one provided with tongue C having curved slotO5, and the otherwith mortiseD,and provided with curved recess D1, and set screw I-I, having shank H', and disk H2 overlapping the curved slot and moving in recess D7 as the shank H' moves in the curved slot O2, substantially as and for the purposes specified.

2. A rule having arms A and B, pivoted together, one provided with tongue C, having curved slot C2 and recess C7, and the other arm having a mortise D, provided with curved recess D7,following the slot C5, and the set screw H having shank H', engaging the side D5, and having disk H2 received into curved recess D7, or recess C7, substantially as and for the purposes specified.

3. A rule having arms as A and B, pivoted together, one of the arms having tongue C and a recess K on each side of the tongue, bounded by the raised edge B2 and a curved slot C2 in the tongue C, the arm A having the end corner projection A', and mortise D, and the set screw H whose shank is in the slot C5, and engages the side of the mortise D, the boundary B2 resting against the end A4 and within the end A' of the arm A when the rule is a right angled one, substantially as and for the purposes specified.

4. A rule having arms as A and B pivoted together, one of the arms having tongue C, recess K, bounded by curved edge B' and straight edge B2, a curved slot C5 in the tongue, and arm A having end extension A2 curved, and straight edge A5, and end corner lap A', and mortised, the tongue entering said mortise, and pivoted to the arm A by pivot E, and set screw H having screw shank engaging the arm A, and located in curved slot O3, the set screw also having the disk H2, and that half ofthe mortise D next which the disk is located having a recess receiving the disk, substantially as and for the purposes specified.

5. A rule having arms as A and B pivoted together, one of the arms having tongue C, recess K, bounded by curved edge B and straight edge B2,'a curved slot C3 in the tongue, and arni A having end extension A2 curved, and straight edge A4, and end corner lap A, and mortised, the tongue entering said mortise, and pivoted to the arm A by pivot E, and set screw H having screw shank engaging the arm A, and located in curved slot C3, the

set screw also having the disk H2, and that half of the mortise D next which the disk is located having arrecess receiving the disk, the tongue C having the inclined edge C and the curved edge C2 projecting below the line of the arm B carrying the slot C5, and the back end of the mortise D in arm A provided with the straight edge D and the curved edge D2 respectively impigning against the edges C and C2 of the tongue C, when the rule is made a right angled one, substantially as and for the purposes specified.

JOI-IN K.`LOVE. Attest:

A. S. LUDLoW, K. SMITH. 

